1. Field of the Invention
The invention is directed to an improved commutator for an electrical machine, in particular for an electric motor for actuating drives in motor vehicles.
2. Description of the Prior Art
One commutator known from U.S. Pat. No. 6,285,106 B1 has a hollow-cylindrical commutator body of insulating material, which can be mounted on the rotor shaft of a commutator machine in a manner fixed against relative rotation, and on whose outer circumference the commutator laminations are disposed with gap spacing from one another, side by side in the circumferential direction. Each commutator lamination has an integral connection lug or connection hook for connecting the coils of a rotor winding that is wound in a known manner in slots of a ferromagnetic rotor body that is seated on the rotor shaft in a manner fixed against relative rotation. In order, to reduce the spark development which occurs in the commutation during operation of the commutator machine and which is the cause of electromagnetic interfering radiation, an indentation is machined into the face end of the commutator body facing away from the connection hooks, into which indentation an interference suppressor disk, such as a varistor, is placed such that one annular disk face of it rests on the bottom of the indentation, and the other annular disk face, carrying connection electrodes, points outward. A contact ring is pressed onto the interference suppressor disk and electrically conductively connects the connection electrodes with the commutator laminations. The contact ring has a basic ring of insulating material, with many first and second contacts, each connected to one another. The number of first contacts and the number of second contacts is equivalent to the number of commutator laminations, or the equally large number of connection electrodes on the interference suppressor disk. Each first contact rests on a connection electrode, and each second contact, electrically conductively connected to the first contact, rests with mechanical prestressing on the underside of one of the commutator laminations that protrude at the end past the indentation. A cap that presses the first contacts against the connection electrodes and that is locked in the indentation is pressed onto the contact ring.